Millions of patients worldwide suffer from a chronic itching condition with no identifiable cause — a condition known as chronic pruritus of unknown origin (CPUO) — that has no targeted therapies approved to treat it. Many of these patients suffer for years with little relief, but a new study may provide hope for future treatments. Patients were found to have lower than normal levels of metabolite biomarkers in the blood plasma that could point to a cause of their excruciating symptoms.